Would you be interested in purchasing a modified Airtek DT for use as a Sub Sunk device?

Included is a URL to a web site that has a device used by the free-flight aircraft hobbyists to bring down their aircraft after a pre-set time delay. This type of unit is referred to in the FF world as a "DT" (De-Thermolizer). The DT (through a servo or other device) causes the horizontal stabilizer on the FF aircraft to flip to a vertical position which forces the a/c to begin a falling-leaf decent.

I contacted the builder, Ken Bauer, to see if he had a way to extend the time-base increment and maximum time-out. With a firmware change he can program the timer to count in increments other than 30 seconds. He suggests that he could change the timebase increment to 30 minutes for our application which would give us a maximum time-out period of 20 hours. If we would rather have a different time-out I'm sure he could make it whatever we wanted.

The stand-alone battery that powers the unit could be turned on with a switch operated by some kind of a reach-rod mechanism from the superstructure. After the time-out the unit can activate a micro servo which could release a float (emergency buoy) as a locating device or what ever the sub driver might have in mind.

I have a question in to Ken asking if the "10 second Count-Down to launch window" can be ignored. I don't see any purpose for it in our application. Once the maximum time-out has been programmed during assembly of the sub all I want to do is just turn on the battery to activate the device.

It only becomes worthwhile for Ken if we place an order for a minimum of 10 units at $30 each. I suggested to Ken that we each deal with him individually and when he has ten orders to then make the mods and start shipping units. I have asked him for the details on how to place an order.

I for one am very interested in acquiring one of these units for each sub I build. I will create a poll to get an idea of how many people are interested. Let me know what kind of maximum time-out numbers would be most advantageous. Ken would have to let us know what kind of increment timebase would support a particular time-out.

Rick Nelson

Qualified in Submarines 1965
SCM #2583

"D..n the pressure, Six-Zero feet!"
"Most men would rather die than think, Most of them do!" - Bertrand Russell
"Boomers hide with Pride"

Rick, this unit looks very promising, as I would certainly be interested. I've been looking to maximize recovery efforts by such an emergency buoy system. I had been looking at such a relay timer devise that may offer at least a minimum of 60 minutes of run time before having to reset the timer or face having the buoy deployed. Having the time relay extended out would be great. Regards, Al

We have 6 people who have indicated they are interested in purchasing the modified DT for Sub Sunk Emergency Buoy release. Some have indicated they would like to purchase two units. We are still short the minimum number of 10 units ordered to make this a go.

Are there others who are interested?

For an example of using the modified DT read the Time-out Poll post I put up.

Come on folks there has been a lot of discussion about needing such a lost sub device. Let's go with this modified DT approach. Sign up now so we can get this effort going.

Rick Nelson

Qualified in Submarines 1965
SCM #2583

"D..n the pressure, Six-Zero feet!"
"Most men would rather die than think, Most of them do!" - Bertrand Russell
"Boomers hide with Pride"

With nine "Yes"s on the poll it looks like we have enough people who are willing to purchase the modified DT. We needed to have at least ten or more orders. I know a few of us want to order more that one. That's great.

Based on the other poll on maximum time-outs and talking with Ken we plan on going with 5 minute intervals. Up to 40 interval counts can be programmed into the SS DT so that will give us a range of between 5 minutes and a maximum of 200 minutes for Time-outs.

To order your modified DT, we'll call it the "Sub Sunk DT". I will check with Ken Bauer to see how he wants to handle these orders. The pricing will be $30.00 per SS DT and $5.00 shipping.

I'll get back to you all as soon as I hear back for Ken.

I personally am very excited about the various possibilites with teh SS DT.

Rick Nelson

Qualified in Submarines 1965
SCM #2583

"D..n the pressure, Six-Zero feet!"
"Most men would rather die than think, Most of them do!" - Bertrand Russell
"Boomers hide with Pride"

"For mail orders in the US sending a check is good. Paypal works great but please add an extra 2% to the total to help offset the money that these guys keep in the process. Send paypal to: airtek@verizon.net."

You might want to email Ken when you send in your order and please copy me so I can keep track of who is getting units.

The unit will be programmable in 5 minute intervals. Up to 40 interval counts can be programmed into the SS-DT so that will give us a range of between 5 minutes and a maximum of 200 minutes for Time-outs.

There are only two servo positions, the normal initial position and the DT or release position. A couple of seconds after the DT times out the servo moves back to normal position and will not go to DT position again until another full cycle timeout. You can restart the timer as many times as you want either by pressing the button or powering it up, but the servo will just stay in the initial position. The timer sends a command to the servo to go to the first position with each power up, but if it is already there it won't move.

One useful note. The timer provides not only a signal wire to the servo but also a power wire and a ground wire. The signal wire carries the pulse signal that tells the servo where to go. The power wire is controlled by a mosfet switch so that the servo is only powered on and using battery power during the one second period when it is moving. This is significant because this power signal can be used to control a device directly rather than using a servo. For example the solenoid could be connected directly between the power wire and the ground wire which would be much simpler than using a servo. This switch is good for about 200 to 300mA.

If 200 to 300mA is not enough power to drive your solenoid directly you could use it to drive a small relay that could then be used to complete the circuit between a battery and a large solenoid.

Rick Nelson

Qualified in Submarines 1965
SCM #2583

"D..n the pressure, Six-Zero feet!"
"Most men would rather die than think, Most of them do!" - Bertrand Russell
"Boomers hide with Pride"